Patent · US Expired

Process for manufacturing a semiconductor wafer, a semiconductor wafer, process for manufacturing a semiconductor integrated circuit device, and semiconductor integrated circuit device

US6043114A · kind A · utility

13Cited by
17References
42Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 22, 1997
Grant dateMar 28, 2000
Priority date
Expiry dateSep 22, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10D84/038

Abstract

Over the principal surface of a semiconductor substrate body containing an impurity of a predetermined conduction type, there is formed an epitaxial layer which contains an impurity of the same conduction type as that of the former impurity and the same concentration as the designed one of the former impurity. After this, there are formed a well region which has the same conduction type as that of said impurity and its impurity concentration gradually lowered depthwise of said epitaxial layer. The well region is formed with the gate insulating films of MIS.FETs.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.